Two claims that Biotronik have made for it's Home Monitoring system have intrigued me. First, Biotronik claims as a proven capability of earlier detection than other systems of critical, arrhythmic events. Second, they also claim that they can report these events earlier than other systems.
Let's take the second claim first, Biotronik has created a system with the capability to more quickly notify (e. g., transmit) implant data. The Biotronik mobile capability enables a faster detection and quicker transmission of those events by virtue of its mobile capability. Their claim is rooted in mobility of their monitor and its communication system. So, the second claim appears plausible.
The first claim is more difficult not only because it is more difficult to prove, but because it's more difficult to define. I think of at least two ways the capability could be defined and implemented. One, consider the signal-detection paradigm. I have a drawing that defines the basic signal detection paradigm below.
The objective of detector improvement is to reduce both type 1 and 2 errors. However, often times adjustments are made to alpha or beta to make it look like there's an improvement. For example, if sensitivity is the crucial characteristic, the engineers may be willing to sacrifice an increase in type 1 errors to reduce type 2. (This gets into what's called receiver operating characteristics or ROC. Something for a later blog article.)
I discuss the signal detection paradigm for two reasons. First, the signal detection paradigm is an engineering and scientific touchstone that I'll refer to in later articles. Second, it allows one to assess just what is accurate detection, increasing sensitivity, etc.
Thus Biotronik's claim of earlier detection could be real or it could reflect Biotronik's acceptance of more type 1 errors in order to raise sensitivity. This could lead to earlier detection but at the expense of increasing the likelihood of type 1 errors. In the next article, I'll explore ways to improve detection capabilities, not by increasing accuracy of a particular detector, but by increasing the number of different detectors.
Early detection could also be interpreted as predictive. This is the more difficult than simple detection. This would be the computed likelihood of a particular event based on one or more measurements. This does not fit into the simple signal detection paradigm. It often involves finding a pattern and extrapolation. Or it could involve finding a predecessor indicator; finding a condition that is a know precondition to the target. The specifics of a predictive capability will be discussed in a later article.
This ends the Introduction. The next article will discuss detection capabilities in greater detail.